Editing Prague astronomical clock

{{Short description|Medieval astronomical clock on the Old Town Hall building in Prague, Czech Republic}}
{{expand Czech|topic=struct|date=March 2024}}
{{Infobox artwork
| title               = Prague astronomical clock
| italic title        = no
| other_language_1    = Czech
| other_title_1       = Pražský orloj
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| image               = Astronomical Clock (8341899828).jpg
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| alt                 = Prague astronomical clock
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| city                = [[Prague 1]], Czech Republic
| coordinates         = {{Coord|50|05|13.23|N|14|25|15.30|E|type:landmark|display=inline, title}}
| pushpin_map         = Czech Republic Prague Central
| pushpin_map_caption = Location in Prague
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| preceded_by         = <!-- preceding work by the same artist -->
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| website             = {{URL|https://www.prague.eu/en/object/places/3129/astronomical-clock}} 
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The '''Prague astronomical clock''' or '''Prague Orloj''' ({{Langx|cs|Pražský orloj}} {{IPA|cs|praʃskiː orloj|}}) is a [[Middle Ages|medieval]] [[astronomical clock]] attached to the [[Old Town Hall (Prague)|Old Town Hall]] in [[Prague]], the capital of the [[Czech Republic]].

== Description ==
The Orloj is mounted on the southern wall of [[Old Town Hall (Prague)|Old Town Hall]] in the [[Old Town Square]]. The clock mechanism has three main components&nbsp;– the astronomical dial, representing the position of the [[Sun]] and [[Moon]] in the sky and displaying various astronomical details; statues of various [[Saint#Catholic Church|Catholic saints]] stand on either side of the clock; "The Walk of the [[Apostles in the New Testament|Apostles]]", an [[hour]]ly show of moving Apostle figures and other sculptures, notably a figure of a skeleton that represents [[Personifications of death|Death]], striking the time; and a calendar dial with medallions representing the months. According to local legend, the city will suffer if the clock is neglected and its good operation is placed in jeopardy; a ghost, mounted on the clock, was supposed to nod its head in confirmation. According to the legend, the only hope was represented by a boy born on New Year's night.<ref name="PCL-Legends of clock">{{Cite web |title=Legends Of The Old Town Astronomical Clock |url=http://www.praguecityline.com/prague-monuments/legends-of-the-old-town-astronomical-clock |archive-url=https://web.archive.org/web/20141006082818/http://www.praguecityline.com/prague-monuments/legends-of-the-old-town-astronomical-clock |url-status=usurped |archive-date=October 6, 2014 |website=Prague City Line |access-date=18 June 2014}}</ref>

== History ==
[[File:Prague Clock Tower.jpg|thumb|upright|left|The clock tower]]
The oldest part of the Orloj, the mechanical clock and astronomical dial, dates back to 1410, when it was created by horologist [[Mikuláš of Kadaň]] and [[Charles University]] professor of mathematics and astronomy [[Jan Šindel]]. The first recorded mention of the clock was on 9 October 1410.<ref>{{Cite web |url=http://www.orloj.eu/cs/orloj_historie.htm |title=Stručná historie Pražského orloje |language=cs |access-date=9 May 2014}}</ref> Later, presumably around 1490, the calendar dial was added and the clock facade was decorated with [[Gothic architecture|gothic]] sculptures.

Formerly, it was believed that the Orloj was constructed in 1490 by clockmaster Jan Růže (also called Hanuš); this is now known to be a historical mistake. A legend, recounted by [[Alois Jirásek]], has it that the clockmaker Hanuš was blinded on the order of the Prague Councillors so that he could not repeat his work; in turn, he disabled the clock, and no one was able to repair it for the next hundred years.

In 1552 it was repaired by Jan Táborský (1500–1572), master clockmaker of Klokotská Hora, who also wrote a report of the clock where he mentioned Hanuš as the maker of this clock. This mistake, corrected by Zdeněk Horský,<ref>Horský, ''Poznávání vesmíru'', 1962. with a copy of the documents from 1410.</ref> was due to an incorrect interpretation of records from the period. The mistaken assumption that Hanuš was the maker is probably connected with his reconstruction of the Old Town Hall in the years 1470–1473. The clock stopped working many times in the centuries after 1552, and was repaired many times. The legend was used as the main plot in the 2008 animated film ''[[Goat Story|Goat story&nbsp;– The Old Prague Legends]]''.

In 1629 or 1659 wooden statues were added, and figures of the Apostles were added after a major repair in 1787–1791. During the next major repair in the years 1865–1866 the golden figure of a crowing rooster was added.

[[File:Astronomical Clock around 1942 during Nazi occupation World War II.jpg|thumb|Astronomical Clock during Nazi occupation.]]
The Orloj suffered heavy damage on 7 and especially 8 May 1945, during the [[Prague uprising]], when the Nazis fired on the south-west side of the [[Old Town Square]] from several [[Armoured fighting vehicle|armoured vehicles]] in an unsuccessful attempt to destroy one of the centers of the uprising. The hall and nearby buildings burned, along with the wooden sculptures on the clock and the calendar dial face made by [[Josef Mánes]].<ref name="tank">{{Cite web|title=Zničil orloj zásah z německého tanku?|url=http://www.orloj.eu/cs/otazniky_omyly_tank.htm | website=Pražský orloj– The Prague Astronomical Clock | access-date=29 May 2016}}</ref> After significant effort, the machinery was repaired, the wooden Apostles restored by [[Vojtěch Sucharda]], and the Orloj started working again in 1948.<ref>''Survey of the Reconstruction and Repairs of the Prague Astronomical Clock in the 19th and 20th Century'', by Vaclav Heisler; Publisher: National Technical Museum; Praha; undated typescripts from mid-1990s; English translation from a Czech original</ref>

The Orloj was renovated in autumn 2005, when the statues and the lower calendar ring were restored. The wooden statues were covered with a net to keep pigeons away.

The last renovation of the astronomical clock was carried out from January to September 2018, following a reconstruction of the Old Town Tower. During the renovation, an electric clock mechanism that had been in operation since 1948 was replaced by an original mechanism from the 1860s.<ref>{{Cite news|url=https://www.irozhlas.cz/veda-technologie/historie/staromestsky-orloj-oprava-renovace-spusteni-mechanismus-staromestska-radnice_1809282210_pla |title=Staroměstský orloj se po rekonstrukci znova rozběhl, elektrický pohon nahradila původní mechanika|work=iROZHLAS|access-date=2018-10-24|language=cs}}</ref>

=== 600th anniversary ===
On 9 October 2010, the Orloj's 600th anniversary was celebrated with a light show on the face of the clock tower. Two projectors were used to project several animated videos on the clock. The videos showed it being built, torn down, rebuilt, and peeled away to show its internal mechanisms and the famous animated figures, as well as various events in the clock's history. The video interacted with the tower's architecture, such as rain rolling off the arch, and showing the passage of time with moving shadows.<ref>{{Cite web |url=https://vimeo.com/15749093 |title=Video mapping during 600 years anniversary of the astrological tower clock situated at Old Town Square in center of Prague |date=11 October 2010 |access-date=9 October 2015}}</ref>

=== 605th anniversary ===
On its 605th anniversary, 9 October 2015, the Orloj appeared on the Google home page as a [[Google Doodle]].<ref name=teleuk-605th-doodle>{{Cite news |last1=Williams |first1=Rhiannon |title=Prague astronomical clock, the oldest of its kind, is 605 years old |url=https://www.telegraph.co.uk/technology/google/google-doodle/11919530/Prague-astronomical-clock-the-oldest-of-its-kind-is-605-years-old.html |access-date=9 October 2015 |work=[[The Daily Telegraph]] |date=9 October 2015 |location=UK}}</ref><ref>{{Cite web|url=https://doodles.google/doodle/605th-anniversary-of-prague-astronomical-clock/|title=605th Anniversary of Prague astronomical clock|work=google.com}}</ref>

=== 2018 reconstruction ===
The Orloj was taken down for reconstruction and replaced by a [[LED display|LED screen]] in early 2018, with the restoration works scheduled to last for the whole summer tourist season of 2018 and the restored actual Orloj eventually being back in service soon enough to commemorate the 100th [[Origins of Czechoslovakia|anniversary of Czechoslovakia]] at the end of October 2018.<ref>{{Cite web|url=https://praha.idnes.cz/obrazovka-orloj-praha-staromestska-radnice-fes-/praha-zpravy.aspx?c=A180315_132338_praha-zpravy_nuc|title=Orloj na pražské Staroměstské radnici nahradila digitální obrazovka|date=2018-03-15|website=iDNES.cz|access-date=2018-06-12}}</ref><ref>{{Cite news|url=https://prazsky.denik.cz/zpravy_region/rekonstrukce-orloje-se-protahne-spusten-bude-az-na-konci-rijna-20180206.html|title=Rekonstrukce orloje se protáhne. Spuštěn bude až na konci října|date=2018-02-06|work=Pražský deník|access-date=2018-06-12|language=cs}}</ref> With the reconstruction and restoration work completed, it resumed operations at 6 p.m. local time on 28 September 2018.<ref>{{Cite news |url=http://www.itv.com/news/2018-09-26/pragues-famous-astronomical-clock-restored-to-former-glory/|title=Prague's famous astronomical clock restored to former glory|publisher=ITV News. 26 September 2018 | access-date=28 September 2018}}</ref><ref>{{Cite news|url=https://prague.tv/en/s72/Directory/c217-Sightseeing-Attractions/n15859-Clock-renovation-gets-mixed-reaction|publisher=Prague TV|title=Clock renovation gets mixed reaction|access-date=11 October 2018|archive-date=8 March 2021|archive-url=https://web.archive.org/web/20210308023829/https://prague.tv/en/s72/Directory/c217-Sightseeing-Attractions/n15859-Clock-renovation-gets-mixed-reaction|url-status=dead}}</ref>

=== 2022 reconstruction controversy ===
The artwork on the Orloj became the center of controversy after a local heritage group noticed the reproduction had "radically changed the appearance, ages, skin tone, dress and even genders of the figures" illustrated by Mánes in 1866.<ref>{{Cite web|url=https://www.theguardian.com/world/2022/jun/02/pragues-orloj-clock-centre-row-artist-amateur-restoration|title=Prague's Orloj clock at centre of row over artist's 'amateur' reproduction|date=2022-06-02|website=theguardian.com|access-date=2022-06-03}}</ref> A member of the Club for Old Prague, Milan Patka, registered a complaint with the [[Ministry of Culture (Czech Republic)|Ministry of Culture]], alleging that in the restoration, painter [[Stanislav Jirčík]] had deviated from the "spirit and detail" of the original.<ref>{{Cite web|url=https://english.radio.cz/was-reconstruction-pragues-famous-astronomical-clock-botched-8752038|title=Was the reconstruction of Prague's famous astronomical clock botched?|date=2022-06-02|website=radio.cz|access-date=2022-06-03}}</ref> The [[National Heritage Inspectorate (Czech Republic)|National Heritage Inspectorate]] began investigations into the allegations.

''The Guardian'' reported that the artist may have put the likenesses of his friends and acquaintances into the work, "possibly as a joke."<ref>{{Cite web|url=https://www.theguardian.com/world/2022/jun/02/pragues-orloj-clock-centre-row-artist-amateur-restoration|title=Prague's Orloj clock at centre of row over artist's 'amateur' reproduction|date=2022-06-02|website=theguardian.com|access-date=2022-06-03}}</ref> Upon this discovery, the Prague city council's deputy mayor for transport and heritage criticized the botched restoration as "banal and done by an amateur" and suggested the city might need to commission a replacement. It is not yet known how the restoration's discrepancy with the original had escaped detection when the work was installed in 2018.

== Astronomical dial ==
{{More citations needed|section|date=October 2019}}
[[File:Schema Orloj en.png|thumb|Functions noted]]
The astronomical dial is a form of mechanical [[astrolabe]], a device used in medieval [[astronomy]]. Alternatively, one may consider the Orloj to be a primitive [[planetarium]], displaying the current orientation of the universe relative to the Earth.

The astronomical dial has a background that represents the standing Earth and sky, and surrounding it operate four main moving components: the zodiacal ring, an outer rotating ring, an icon representing the Sun, and an icon representing the Moon.

=== Stationary background ===
The background represents the Earth and the local view of the sky. The blue circle directly in the centre represents the Earth, and the upper blue is the portion of the sky which is above the [[horizon]]. The red and black areas indicate portions of the sky below the horizon. During the daytime, the Sun sits over the blue part of the background and at night it sits over the black. During dawn or dusk, the mechanical sun is positioned over the red part of the background.

Written on the eastern (left) part of the horizon is ''aurora'' (dawn in [[Latin]]) and ''ortus'' (rising). On the western (right) part is ''occasus'' (sunset), and ''crepusculum'' (twilight).

Golden [[Roman numerals]] at the outer edge of blue circle are the timescale of a normal 24-hour day and indicate time in local Prague time, or [[Central European Time]]. Curved golden lines dividing the blue part of dial into 12 parts are marks for unequal "[[hour]]s". These hours are defined as 1/12 of the time between sunrise and sunset, and vary as the days grow longer or shorter during the year.

=== Zodiacal ring ===
[[File:Czech-2013-Prague-Astronomical clock face.jpg|thumb|left|Astronomical dial]]
Inside the large black outer circle lies another movable circle marked with the signs of the [[zodiac]] which indicates the location of the Sun on the [[ecliptic]]. The signs are shown in anticlockwise order. In the photograph accompanying this section, the Sun is currently moving anticlockwise from [[Cancer (astrology)|Cancer]] into [[Leo (astrology)|Leo]].

The displacement of the zodiac circle results from the use of a [[stereographic projection]] of the ecliptic plane using the North pole as the basis of the projection. This is commonly seen in [[astronomical clock]]s of the period.

The small golden star shows the position of the [[March equinox|vernal equinox]], and [[sidereal time]] can be read on the scale with golden Roman numerals. The zodiac is on the 365-tooth gear<ref>{{Cite web | url=http://www.orloj.eu/en/orloj_jici.htm | title=Pražský orloj – the Prague Astronomical Clock }}</ref> inside the machine. This gear is connected to the Sun gear and the Moon gear by a 24-tooth gear.

=== Old Czech time scale ===
[[File:Prague Astronomical Clock.png|thumb|right|upright|The clock tower on a Christmas night]]
At the outer edge of the clock, golden [[Schwabacher]] numerals are set on a black background. These numbers indicate Old Czech Time (or [[Hour#Counting from sunset|Italian hours]]), with 24 indicating the time of sunset, which varies during the year from as early as 16:00 in winter to 20:16 in summer. This ring moves back and forth during the year to coincide with the time of sunset. The outermost diameter of the ring is approximately 300cm (9.8ft).<ref>{{Cite web | url=https://www.orloj.eu/en/astro_cifernik.htm | title=Pražský orloj – the Prague Astronomical Clock }}</ref>

=== Sun ===
The golden Sun moves around the zodiacal circle, thus showing its position on the [[ecliptic]]. The Sun is attached to an arm with a golden hand, and together they show the time in three different ways:

# The position of the golden hand over the Roman numerals on the background indicates the time in local Prague time.
# The position of the Sun over the curved golden lines indicates the time in [[Hour#Counting hours|unequal hours]].
# The position of the golden hand over the outer ring indicates the hours passed after sunset in [[Hour#Counting hours|Old Czech Time]].

Additionally, the distance of the Sun from the center of the dial shows the time of sunrise and sunset. The Sun and its hand are on the 366-tooth gear<ref>{{Cite web | url=http://www.orloj.eu/en/orloj_jici.htm | title=Pražský orloj – the Prague Astronomical Clock }}</ref> inside the machine.

=== Moon ===
[[File:La lunaire de Tour horloge.jpg|thumb|left|The Moon sphere is seen showing approximately a quarter moon]]
[[File:PACMoon.png|thumb|right|The unique mechanism inside the Moon]]
The movement of the Moon on the ecliptic is shown similarly to that of the Sun, although the speed is much faster, due to the Moon's orbit around the Earth. The Moon's arm is on the 379-tooth gear inside the clock machine.

The half-silvered, half-black sphere of the Moon also shows the [[Lunar phase]]. The Moon has a 57-tooth gear inside its sphere, and is slowly rotated by a screw-thread attached to a weight, advancing two teeth per day. This movement, powered only by [[gravity]], makes the Orloj unique in the world among astronomical clocks showing the phases of the Moon. The mechanism was created by an unknown maker, probably in the mid-17th century. Unlike the original device, the construction of which was described in a report from 1570, this mechanism produces much smaller deviation from the actual lunar phase of about one day in five years.<ref name="Moon">{{Cite web|last1=Marušák|first1=Stanislav|title=Mysterious Moon|url=http://www.orloj.eu/en/orloj_mesic.htm | website=Pražský orloj&nbsp;– The Prague Astronomical Clock | access-date=29 May 2016}}</ref>{{Clear}}

== Animated figures ==
{| align=center
|+ '''Moving figures'''
| [[File:Statues on Prague Astronomical Clock 2014-01 (landscape mode) 4.jpg|left|280px]]
| [[File:Prazsky orloj sochy apostolove.jpg|left|280px]]
| [[File:Statues on Prague Astronomical Clock 2014-01 (landscape mode) 3.jpg|280px|left]]
|}

The four figures flanking the clock are set in motion on the hour, and represent four things that were despised at the time of the clock's making. From left to right in the photographs, the first is [[Vanitas|vanity]], represented by a figure admiring himself in a mirror. Next, the [[miser]] holding a [[Money bag|bag of gold]] represents [[greed]] or [[usury]]. Across the clock stands [[Personifications of death|Death]], a skeleton that strikes the time upon the hour. Finally, there is a Turkish figure representing [[lust]] and earthly pleasures. On the hour, the skeleton rings the bell and immediately all other figures shake their heads side to side, signifying their unreadiness "to go".

Every hour of the day, statues of the [[Apostles in the New Testament#Lists of the Twelve Apostles in the New Testament|Twelve Apostles]] with their attributes appear at the doorways above the clock. The left and right windows above the astronomical clock slide aside to reveal the Apostles as viewed from the square in this order: [[James the Less]] and [[Saint Peter|Peter]], [[Andrew the Apostle|Andrew]] and [[Saint Matthias|Matthias]], [[Jude the Apostle|Thaddeus]] and [[Philip the Apostle|Philip]], [[Thomas the Apostle|Thomas]] and [[Paul the Apostle|Paul]], [[John the Evangelist|John]] and [[Simon the Zealot|Simon]], [[Barnabas]] and [[Bartholomew the Apostle|Bartholomew]]. Unlike the list of the Twelve Apostles mentioned in the canonical gospels, [[James the Great]] and [[Matthew the Apostle|Matthew]] are missing, replaced by Paul and Barnabas.

== Calendar ==
{| align=center
|+ '''Calendar overview and detail'''
| [[File:Rekonstrukce Staroměstské radnice 1AAB1356.jpg|left|275px]]
| [[File:Prague Astronomical Clock Detail.jpg <!-- replacing Image:Prazsky orloj kalendar detail.jpg -->|left|275px]]
|}

The calendar plate below the clock was replaced by a copy in 1880. The original made by Josef Mánes is stored in the Prague City Museum.<ref name="The Old Town Astronomical Clock">{{Cite web |url=http://www.praguecityline.com/prague-monuments/the-old-town-astronomical-clock-calendar-board |archive-url=https://web.archive.org/web/20160507140559/http://www.praguecityline.com/prague-monuments/the-old-town-astronomical-clock-calendar-board |url-status=usurped |archive-date=May 7, 2016 |website=Prague City Line |access-date=9 October 2015 |title=The Old Town Astronomical Clock}}</ref> On the edge of the circle is a church calendar with fixed [[holiday]]s and the names of 365 saints. The board displays allegories of the [[month]]s. Smaller images represent [[Astrological sign|zodiac signs]].

Next to the calendar stands a [[philosopher]], [[Michael (archangel)|archangel Michael]] pointing at the top of the dial, an [[astronomer]] and a [[chronicle]]r.

== See also ==
{{Portal|Czech Republic}}
* [[Antikythera mechanism]]
* [[Armillary sphere]]
* [[Equation of time]]
* [[Geocentric model]]
* [[Horology]]
* [[Orrery]]
* [[Šindel sequence]]
* [[Torquetum]]
* A replica of the clock is in [[Mapo District]], [[Seoul]]

== References ==
=== Cited sources ===
{{Reflist|30em}}

=== Other sources ===
* {{Cite book |last=Horský |first=Zdeněk |title=Pražský orloj |publisher=Panorama |date=1988 |language=cs |location=Prague }}
* {{cite book | last=Malina | first=Jakub | title=The Prague Horologe: A Guide to the History and Esoteric Concept of the Astronomical Clock in Prague | series=Esoteric Prague | date=2005 | isbn=978-80-7281-204-2}}

== External links ==
{{Commons category|Prague Astronomical Clock}}
* {{Official website|http://www.orloj.eu/en/home1.htm}}
* {{YouTube|NebyX6-GUTM|The Astronomical Clock of Prague&nbsp;– video with details about the clock}}
* {{YouTube|Xk9lwsenZOo|Video of the clock's hourly chime}}
* [http://blog.longnow.org/2010/10/13/prague-astronomical-clock-600th-anniversary-show/ Orloj&nbsp;– 600th Anniversary Show]
* [http://www.wijzerweb.be/prague.html Animated explanation of the movements of the clock] {{Webarchive|url=https://web.archive.org/web/20201121173324/http://www.wijzerweb.be/prague.html |date=2020-11-21 }}

{{Astronomical clocks}}
{{Authority control}}

[[Category:Astronomical clocks in the Czech Republic]]
[[Category:Buildings and structures in Prague]]
[[Category:Clock towers in the Czech Republic]]
[[Category:History of astrology]]
[[Category:Towers completed in the 15th century]]
[[Category:Buildings and structures completed in 1410]]
[[Category:1410s in Europe]]
[[Category:Tourist attractions in Prague]]
[[Category:Old Town (Prague)]]